Biomedical subjects
Publications and source records attributed to J May.
Venous occlusion is an uncommon complication of transvenous cardiac pacing. Fibrotic occlusion of the right subclavian and innominate veins and stenosis of the left innominate vein, after the insertion of transvenous pacing wire, was corrected surgically with an external iliac vein graft.
Three physicochemical methods (HPLC, NMR spectroscopy, and HPLC of a derivative) have been used to measure parthenolide in authenticated Tanacetum parthenium (feverfew) and in several commercial purported feverfew products. A bioassay based on inhibition of the secretory activity of blood platelets by extracts of feverfew in comparison with parthenolide was also used. Similar results were obtained for all three physicochemical assays and also for the bioassay. Thus different methodologies yield consistent values for parthenolide content of feverfew preparations. Parthenolide appears to be mainly responsible for the antisecretory effects of extracts of feverfew. Authenticated Tanacetum parthenium grown in the UK contained a high level of parthenolide in leaves, flowering tops and seeds but a low level in stalks and roots. The level of parthenolide in powdered leaf material fell during storage. The purported feverfew products varied widely in their parthenolide content and in some products parthenolide was not detected. Possible reasons for the variation in parthenolide content are discussed. Since therapeutic efficacy has only been demonstrated for preparations of feverfew that contain parthenolide, it is suggested that manufacturers of feverfew products should use measurements of parthenolide as a means of standardization and quality control.
In families the whole is greater than the sum of the parts. All family members are interconnected, interdependent and exist in a fragile balance. What happens to one affects all the others. Having a child with a chronic illness or disability creates permanent change in family dynamics. Often roles become stratified, communication may break down and personal needs can go unmet. Professionals, in moving toward a family centered model of service delivery, must assist all family members in regaining personal equilibrium. This article identifies strategies for practitioners to empower families in this critical process.
In the face of increasing heterogeneity among American families, it is imperative health care systems and professionals be culturally sensitive and competent. As we enter a new era of parent-professional collaboration, where services are family centered, community based and coordinated, grasping the richness, and complexity, of working with a pluralistic clientele is essential. Self-awareness regarding one's personal heritage, and the desire to know how clients view and accept Western health practices, are the beginnings of cultural competence. This article examines various strategies professionals can use to assure that such competent programs are a norm.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Between 1968 and 1989, 160 patients underwent aortorenal bypass for renovascular hypertension. During the same interval, 13 patients had ex-vivo bench repair of complex renal arterial pathology. There were eight men and five women, with a mean age of 36 years. Twelve of the 13 patients had fibromuscular disease; one had atherosclerosis. Twelve patients had renovascular hypertension with complex stenotic disease beyond the main renal artery. Seven of these also had an associated renal aneurysm as did the sole normotensive patient. Saphenous vein patch or bypass were used to correct stenotic segments in four patients, while the remaining nine patients had excision of stenotic or aneurysmal segments with primary arterial anastomosis. There were no deaths in the series. One kidney was lost because of arterial thrombosis. One patient required reoperation to control postoperative bleeding. Nine of the 12 patients with renovascular hypertension were normotensive off medication, and three were improved, with reduced medication controlling their blood pressure. Ureteric obstruction occurred in two patients; this settled spontaneously in one patient and was corrected by reoperation in the other. From this experience, we conclude that bench repair is a safe and effective way to maximize salvage of kidneys affected by complex arterial pathology.
Between July 1980 and July 1988, 478 consecutive patients underwent aortic aneurysm operations at Royal Prince Alfred Hospital. Renal function was assessed by measurement of serum creatinine levels. The left renal vein was divided in 28 (8%) of the 355 patients undergoing elective aneurysm resection. The mean immediate postoperative creatinine values were significantly higher after left renal vein division, 193 +/- 174 mumol/L, compared to 133 +/- 93 mumol/l for those whose left renal vein remained intact (p less than 0.05 by Mann-Whitney U test). After one month, serum creatinine levels had decreased but were still significantly higher in those patients in whom the left renal vein had been divided, 170 +/- 166 mumol/l, compared to those in whom it was left intact 109 +/- 49 mumol/l (p less than 0.05 by Mann-Whitney U test). The suprarenal aorta was cross-clamped in seven (25%) of the 28 patients in whom the left renal vein was divided, compared to 21 (6%) of the 327 with the left renal vein intact. A rise in creatinine level was observed after suprarenal aortic cross-clamping. The left renal vein was divided in 17 (14%) of the 123 patients having emergency surgery for ruptured aortic aneurysm, 61 (49%) of whom survived more than 30 days. The mean immediate postoperative creatinine values were significantly higher after left renal vein division, 426 +/- 277 mumol/l, compared to those in whom the vein was left intact, 178 +/- 136 mumol/l (p less than 0.05 by Mann-Whitney U test). After one month, serum creatinine levels were still significantly higher in those patients in whom the left renal vein had been divided. Although division of the left renal vein is a useful way to improve exposure of the juxtarenal aorta, the maneuver is associated with an adverse effect on renal function.
We have reviewed our experience with percutaneous transluminal angioplasty of contralateral iliac stenosis and extraanatomic bypass of the occluded iliac artery. Twenty-two men and nine women with a mean age of 65 years (range 46 to 84) presented with symptomatic iliac occlusive disease. Twenty-four (77%) had disabling claudication, four (13%) rest pain, and three (10%) ischemic tissue loss. Six (19%) had undergone previous vascular reconstructive procedures. All had an occluded iliac artery on the symptomatic side and greater than 50% stenosis of the contralateral iliac artery. Percutaneous transluminal angioplasty of the iliac stenosis was done prior to extraanatomic bypass, using polytetrafluoroethylene. There were six late deaths after discharge. The only significant complication was a femoral artery thrombosis which was corrected when the bypass graft was performed. Cumulative primary graft patency was 89% at one year and 81% at three years. The crossover graft occluded in six patients, five within 48 months of surgery, and one after nine years. One of these occluded grafts was salvaged by thrombectomy, for a secondary patency rate of 85% at three years. Two patients required aortobifemoral bypass, one an iliobifemoral bypass and one an ilioprofunda bypass. One patient operated upon for rest pain came to below-knee amputation. Mean resting ankle/brachial systolic pressure index increased significantly on the side of the iliac occlusion from 0.35 +/- 0.21 to 0.70 +/- 0.20 (p less than 0.05, paired t test) after the combined procedure. There was no significant difference in the mean resting ankle/brachial systolic pressure index on the contralateral side (0.60 +/- 0.22 to 0.65 +/- 0.27, ns).(ABSTRACT TRUNCATED AT 250 WORDS)
It has been shown that, under certain circumstances, anxiety is associated with a processing bias favouring threatening information. To explain why this bias is apparent only on certain cognitive tasks, it has recently been proposed that the bias operates only when there is competition for processing resources. The present study sought to replicate previous evidence for the 'competition' hypothesis, while taking into account a potential confounding factor of word categorization in the stimulus materials. Anxious patients and normal controls were compared on their lexical decision times for threatening, categorized neutral and uncategorized neutral words that were presented either alone or accompanied by irrelevant nonword stimuli (i.e. absence vs presence of competition). The results were only partially consistent with previous findings and highlighted the importance of considering separately the effects of word valence and word categorization. When the latter was taken into account, the results indicated that an anxiety-related bias was only evident when there was competition for processing resources and when the information was presented outside the focus of Ss' attention. A modified version of the competition hypothesis was proposed in the light of these results and previous research into attentional biases in anxiety.
In the 1st of 2 experiments, currently clinically anxious, recovered clinically anxious, and normal control subjects were presented with a mixture of unambiguous and ambiguous sentences; both threatening and nonthreatening interpretations were possible for the latter. A subsequent recognition-memory test indicated that the currently anxious subjects were more likely than normal control and recovered anxious subjects to interpret the ambiguous sentences in a threatening fashion rather than in a nonthreatening fashion. This suggests that the biased interpretation of ambiguity found in currently anxious subjects reflected their anxious mood state. A 2nd experiment established that the difference in interpretative processes between currently anxious and control subjects was not due to response bias and that the interpretative bias was a reasonably general one.
Laser-assisted balloon angioplasty has the potential to reduce mortality and morbidity by replacing aorto-femoral bypass operations in patients with occlusion of the iliac arteries. We present our early experience with 16 patients undergoing this procedure, using a Cardiolase neodymium:yttrium aluminum garnet (Nd:YAG) laser in the operating room. Initial recanalization was achieved in 14 of the 16 patients. Early re-occlusion occurred in 4 patients, one of whom had a successful repeat laser angioplasty. This patient, together with the remaining 10 patients with successful initial recanalization remain patent at a mean follow-up period of 10 months. There were no deaths or chest complications. Angiographically demonstrated arterial perforation occurred in 2 patients, neither of whom required operation on the perforated segment. We conclude that recanalization of the iliac arteries is possible and safe. The procedure is unlikely to replace aorto-femoral bypass until the proportion of early failures is reduced. This may require larger probes or the immediate placement of intra-arterial stents following laser angioplasty.
A panel of immunotoxins was constructed by chemically attaching the ribosome-inactivating proteins abrin A chain, ricin A chain, gelonin, and momordin to the monoclonal mouse IgG2a antibody Fib75 by means of a disulfide linkage. All the immunotoxins were toxic in tissue culture to the EJ human bladder carcinoma cell line expressing the antigen recognized by Fib75, inhibiting the incorporation of [3H]leucine by 50% at concentrations between 1 x 10(-10) M and 8 x 10(-10) M. The pharmacokinetics of the immunotoxins in the normal Wistar rat was determined following i.v. administration. The concentrations of intact immunotoxin in serum samples taken at various intervals after injection for up to 24 h were measured by solid-phase enzyme-linked immunosorbent assays specific for each of the four different ribosome-inactivating proteins. The Fib75 immunotoxins were cleared from the circulation with comparable, but not identical, biphasic kinetics best described by a two compartment open pharmacokinetic model. The alpha-phase half-lives of the panel, between 0.35 and 0.71 h, were similar. The beta-phase half-life of Fib75-abrin A chain, 13.3 h, was significantly longer than the beta-phase half-lives of Fib75-ricin A chain, Fib75-gelonin, and Fib75-momordin, between 7.5 and 8.6 h. Fib75-abrin A chain was found to be about 3- to 4-fold more resistant than the other immunotoxins to breakdown by reduction of the disulfide linkage between the A chain and the antibody with glutathione in vitro. This suggests that the longer serum half-life of Fib75-abrin A chain may have been due to greater stability against reduction in vivo. Analysis of serum samples obtained up to 24 h after injection of Fib75-abrin A chain revealed that the chemically intact immunotoxin present in the circulation retained full cytotoxic activity. An abrin A chain immunotoxin made with a different monoclonal mouse IgG2a antibody was also found to be more stable against reduction by glutathione in vitro than an analogous ricin A chain immunotoxin. Thus, abrin A chain may posses unique molecular properties that endow immunotoxins made with this A chain with greater stability in vivo than immunotoxins made with ricin A chain or other ribosome-inactivating proteins.
Glucose (10-50 mM) added to samples of citrated whole blood increased the spontaneous platelet aggregation (SPA) that was observed upon stirring the samples, in a dose-dependent but time-independent manner. EDTA prevented and also reversed the SPA that occurred in the presence of glucose. Galactose, fructose and 2-deoxyglucose, but not sorbitol and sucrose, had effects on SPA similar to those of glucose. The effect of glucose on SPA in whole blood could not be specifically inhibited by tetramethylene glutaric acid (an inhibitor of aldose reductase). SPA was not affected by pentoxifylline, but was markedly reduced by chlorpromazine. We previously found that glucose, galactose, fructose and 2-deoxyglucose, but not sorbitol and sucrose, render red blood cells more fragile, and the results obtained in the present study provide further evidence that glucose as well as other reducing sugars potentiate SPA in whole blood by liberating ADP or other aggregating material from red blood cells.
Sixty-five children over one year and under 15 years of age began treatment for end-stage renal failure between 1973 and 1988. Sixty-one renal transplants were performed in 53 children, 39 of these were from living donors (38 were first-degree relatives and one was an emotionally related volunteer). Thirteen children, of whom seven had received transplants and six had not, died, including three children with functioning transplants; nine deaths occurred in the first eight years of the programme. Cumulative five-year and 10-year patient survival rates were 78% and 75%, respectively. Eighteen transplants failed, 12 as a result of rejection, five as a result of disease recurrence and one due to primary non-function. Cumulative five-year and 10-year transplant survival rates for first grafts were 66% and 53%, respectively. For living donor transplants these rates were 85% and 68%, respectively. Growth rates fell by 0.4 +/- 0.05 standard deviation score (SDS) per year in children undergoing dialysis, were normal in children with renal transplants receiving prednisone (change in SDS per year, -0.02 +/- 0.08) and increased by 0.36 +/- 0.07 SDS per year in children with transplants receiving cyclosporin A alone. Currently, 32 (82%) of 39 transplant recipients and 7 (58%) of 12 patients undergoing dialysis attend school or work full time. Although both dialysis and transplantation are acceptable therapies for children with end-stage renal failure, successful transplantation provides the best opportunity for satisfactory growth and development.
Two experimental tasks were used to investigate the nature of a previously documented bias in attention associated with anxiety. Results from the first task failed to reveal any differences between anxious and nonanxious subjects, either in attention focusing or selective search for letters. The second task, with words as targets and distractors, suggested that selective search was less efficient in anxious subjects when distractors were present. Currently anxious subjects were slower than controls when required to search for the target among distractors of any type, whereas both currently anxious and recovered subjects were slower when the distractors were threatening words. It was therefore suggested that a bias favoring threat cues during perceptual search is an enduring feature of individuals vulnerable to anxiety, rather than a transient consequence of current mood state alone.
The surgical indication for spontaneous cerebellar hemorrhage is not as controversial as the operative management of intracranial hemorrhage. Timing of the operation is crucial: intervening too early can produce an additional strain on the patient and an increased risk, while waiting too long to evacuate the hematoma can be fatal. This dilemma may be a factor in the relatively high mortality and morbidity rates following both operative and conservative treatment that have been reported in the literature (42.5% and 30%, respectively). In long-term studies on 14 patients, the authors have shown that stereotactic puncture and fibrinolysis for cerebellar hemorrhage is a valuable alternative to treatments used currently. The method consists of computerized tomography (CT)-guided stereotactic puncture and partial evacuation of the hematoma. After fibrinolysis with urokinase, the residual hematoma can be completely evacuated via a catheter introduced into the cavity of the hematoma. Only one of the 14 patients died in the direct postoperative phase; the remaining patients were enjoying a good to very good quality of life 6 months after the acute event. Two patients subsequently died as a result of pneumonia and cerebral infarction, respectively; both conditions were unrelated to the hemorrhage. The authors conclude that the CT-guided stereotactic method is simple, effective, and safe, and can be applied to patients of any age.
We studied projections from extrastriate visual areas and the superior colliculus to the pontine nuclei of monkeys using degeneration staining and transport of wheatgerm agglutinin horseradish peroxidase, and 3H amino acids. The superior colliculus and the extrastriate cortical visual areas both project to the ipsilateral dorsolateral region of the pontine nuclei. The projections from extrastriate visual cortex occupy a much larger territory within the pontine nuclei than those from the superior colliculus. The superficial laminae of the superior colliculus project only to the ipsilateral pontine nuclei. The projection to the contralateral nucleus reticularis tegmenti pontis arises from cells in deeper laminae within the superior colliculus.